Automatic interlock for elevator hatchway doors



J. F. GREEN Dec. 29, 1959 AUTOMATIC INTERLOCK FOR ELEVATOR HATCHWAY DOORS 2 Sheets-Sheet 1 Filed April 26, 1956 fizdzz for";

J. F. GREEN 2,918,988

AUTOMATIC INTERLOCK FOR ELEVATOR HATCHWAY DOORS Dec. 29, 1959 2 Sheets-Sheet 2 Filed April 26, 1956 United States Patent AUTOMATIC INTERLOCK FOR ELEVATOR HATCHWAY DOORS Joseph F. Green, Moline, IIL, assignor, by mesne assignments, to Montgomery Elevator Company, a corporation of Delaware Application April 26, 1956, Serial No. 588,817

4 Claims. (Cl. 187-31) This invention relates to an automatic interlocking mechanism for hinged elevator hatchway doors and more particularly to an interlocking mechanism for hlnged double doors.

The development of automatic passenger operated elevators has produced many problems, one of which is the provision of automatic hatchway door interlocking mechanism which permits the hatchway doors to be opened either from within the car or from the floor side of the hatchway when the elevator is stopped at a floor and at no other time. The conversion of existing manual installations to autornatic complicates the problem, because of the need to devise a mechanism which requires the least possible modification of the existing manual components.

Many types of interlocking mechanisms have been devised for use with sliding hatchway doors. However, in some elevator installations, especially freight elevators in the meat packing industry, hinged doors, and particularly hinged double doors, are quite common and usually preferred. The automatic interlocking mechanisms used with sliding doors are not adaptable for use with swinging double doors because the door locking portions must engage near the center of the door opening; and the interlocking mechanism thus requires a portion extending across one door from the free edge of the door toward the hinge margin with which the automatic interlock may engage. This must be quite flat to maintain clearance between the elevator car and hatchway. Furthermore, to permit inexpensive conversion of existing manual elevators to automatic operation the interlock must require the least possible modification of existing mechanisms.

The present invention provides an automatic interlock meeting the above requirements. There is no significant modification of the existing hinged door latching means commonly used with manually controlled elevator cars. The device of the present invention is basically an attachment which can be applied to the latch when an elevator is converted from manual to automatic operation. for operating the door latch from the corridor side, while an interlock member pivoted on the auxiliary arm extends across the door and projects a short distance past the hinges where it may be engaged by a locking arm of a bell crank. The bell crank is rotated by a standard type of retiring cam which automatically engages the bell crank when the car stops opposite the door, thereby releasing the interlock member and unlocking the latching means. I

Thus with the interlock mechanism of this device the elevator hatchway doors remain locked at all times except when the elevator car has stopped opposite the door, at which time the door can be opened from either side.

The interlock member is a fiat bar parallel to the door and therefore fits easily into the narrow space between the hatchway and the elevator car. Also, the bell crank can be mounted to the side so as not to interfere with An auxiliary door latch control arm is provided Patented Dec. 29, 1959 the clearance except for the locking arm which can be parallel to the door.

Further, there is no structure extending across the lintel and free movement of the doors when unlocked is permitted.

The invention is illustrated in a preferred embodiment in the accompanying drawings in which:

Fig. l is a fragmentary front elevational view of the elevator shaft side of an elevator hatchway and doors provided with the interlocking mechanism of this invention, parts being broken away for clarity, the manner of taking Fig. 1 being shown by line 1-1 in Fig. 2;

Fig. 2 is a fragmentary horizontal section taken along line 22 of Fig. 1;

Fig. 3 is a fragmentary elevational view showing the floor side of the hatchway doorway shown in Fig. 1, the building wall being eliminated to show positions of certain parts; and

Fig. 4 is a side elevational view of the retiring cam assembly in actuating contact with the interlock cam follower roller.

While this invention is susceptible of embodiments in many different forms, there is shown in the drawings and will herein be described in detail one specific embodiment, with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the invention to the embodiment illustrated. The scope of the invention will be pointed out in the appended claims.

Referring now to the drawings, and first to Fig. l, a portion of a hatchway door opening 10 is shown having a frame 11 surrounding it, and a corner of an elevator E in the hatchway is shown in Fig. 2. A pair of oppositely opening hinged doors 12 and 13 are hung in the opening on hinges 14, and when closed is latched by latching means, indicated generally at 15, mounted on the door 12. The latching means includes a housing and guideway 15a in which is a vertical latch bar 16 engageable with a latch plate 17 on the upper portion of frame 11 to latch the door 12 in closed position, and a horizontal latch bar 18 engageable with a combined latch plate and switch housing 19 on the door 13 to latch that door. The horizontal latch bar 18 also actuates a switch 28 in housing 19 which is in the motor control circuit so that the motor can be operated to drive the elevator car only when the bar 18 is in the position of Fig. 1, closing the 22 pivoted at 22a on a mounting plate 225. The bell crank has a first arm 23 making a pin-and-slot connection at 23a with vertical latch bar 16 and an upright operating arm 24 which makes a pin-and-slot connection at Ma with the horizontal latch bar 18. Thus as the bell crank is rotated the arms move the latch bars to unlatch the doors and break the power circuit. A cam arm 25 pivoted on the housing 15a is spring urged into contact with a lug 25a on the operating arm to hold the bell crank in a normally latched position. The lower end of operating arm 24 travels in an arcuate guide 24a on the door 12. The mechanism heretofore described is the basic door latching mechanism used for manually controlled elevators.

In accordance with the present invention, auxiliary operating arm means, indicated generally at 26, has a pivot 27 extending through the door 12, an outside arm 28 on the corridor side of the door, and a linking arm 29 on the inside of the door connected by a link 36 to the upright operating arm 24. Thus rotation of auxiliary arm means 26 acts through link 30 to unlatch the door. A counterweight 28a at the top of outside arm 28 swings over center upon full movement of the arm in either direction to retain the arm at either end of its movement.

The door latching means is locked in door latching position by a laterally extending interlock arm 31 which is pivotally connected to the linking arm 29 of auxiliary arm means 26 and is supported .in a bracket 32 on .door 12 for sliding movement. A hook portion 33 of interlock arm 31 extends laterally past the hinges 1.4 and ;lies close to the inner face of the frame 11 of the hatchway opening when door 12 is closed.

Movement of the latch mechanism from the position of Fig. l is normally prevented by an interlock bell crank, indicated generally at 34, which is mounted on a pivot 34a on an upright mounting arm a of an angle bracket 35, an attachingarm 35b of which-is secured to frame 11 adjacent hinges 14. Bell -crink 34 hasa locking arm 36 provided with a flat hook portion 37 Which normally engages the hook portion 33-of interlock arm 31. The interlock arm and both hook :portions 33 and 37 are flat so that they cause the least possible interference with the normal clearancebetween thehatch- Way and the elevator E. As seen in Fig. 2, the doors 12 and 13 are slightly recessed in the frame 11 with respect to the hatchway, and the flat construction of'the upright operating arm 24 and connecting arm 29 of auxiliary arm 26 positions them wholly in this recess so that only the flat bracket 32 and flat interlock arm 31 lie inside the plane of the inner face-offrame ll.

As best seen in Figs. 1 to 3, disengagement of the'bell crank locking arm 36 from the interlock arm 31 is permitted by reason ofthe second arm 38 of bell crank 34 which extends around the corner of elevator E (Fig. 2) and has a'depending actuating portion 39 provided with a follower roller 39a which is contacted by a retiring cam 42 of a retiring cam assembly 40 (Fig. 4) when the doors are to be unlocked.

The retiring cam assembly 40 (Fig. 4) is,mounted on a bracket 41 on the side of the elevator-car E and has a retiring cam 42 which is pivoted at 4 211 on bracket 41 so as to be ,engageable with the follower roller 39a of bell crank 34 to rock the bell crank on pivot 34a and disengage the hook portions 33 and 37 to permit unlatching of the doors. The retiring cam .42 is automatically controlled so that it moves into engagement with the roller 39a of bell crank 34 only after the elevator car has stopped opposite the hatchway opening and moves out of engagement with the bell crank just before the elevator car begins to move away from the hatchway door. Movement of hell crank 34 to unlock the doors lowers follower arm 39 so as to lift the book 37 as seen Thi h P sent i ve on n b u e? ihth 99 mon types of elevator systems so that double swinging hatchway doors are locked in closed position at all times except when the elevator car is stopped opposite them, at which time the doors are automatically unlocked. The doors can-then be opened from the elevator or the floor landing; The elevator drive circuit is ineffective to start the elevator l3 as longasthe doors are open. The mechanism-makesfull use of the existing elevator hatchway door latches andconventional activating elements for ,a retiring cam, and occupies .a minimum of the critical space within the hatehway.

I claim:-

1. An automatic interlocking mechanism for a -hinged door of an elevator hatchway comprising: door latching means mounted on the door adjacent its free edge and movable between a door latching position and a release position, saiddoor latching means having operating arm means both inside and outside the door; an interlock member which is connected to a portion of the door latching means and extends laterally along the inside of the door, said interlock member having aportion extending past the hinge line of the door; a supporting bracket mountedin the hatchway and having a mounting arm which is in the spaceat the side of the elevator car; a bell crank pivotally mounted on said mounting arm on a horizontal axis which is in a plane parallel to that of the interlock member, said bell crank having a locking arm in the plane oflthe interlock member and normally engaged therewith, and having an actuating arm in the space at the side of the elevatorcar; a cam follower on said actuating arm in a position which is clear of the mounting arm; and cam means on the side of the elevator car which contacts said cam follower to rock the bell crank on its pivot and lift the lockingarm out of engagement withthe interlock member when the car is opposite the hatchway door. i

2. In an elevator unit having an elevator car mounted for movement in a hatchway which isprovided with a doorway, a door frame surrounding the doorway, and a door hingedly mounted on said frame at one side of the doorway, interlock comprising: door latching meansmourited on the door adjacent its free edge and movablebetween a door latching position and a release position, said door latching means having operating arm means both inside and outside the door; an interlock member whichis connected to a portion of the door latching means and extends laterally along the inside :of the door said interin Fig. 1. As viewed in Fig. 2, hook 37 swings upwardly from the plane of the paper, so that its pivotal movement on pivot 34a moves it slightly toward the elevator E, and away from frame 11.

The retiring cam assembly 40, a type which has long been used to actuate elevator door interlocks,,includes a torque motor 43 mountedon the bracket v41 directly above the retiring cam, the motor having a shaft 44 provided with a crank 45 which is linked to the retiring cam by an operating rod 46. Torque motor 43 is controlled by conventional control components in such .a manner that when the elevator motor circuit is closed the torque motor circuit also is closed,; and vice versa. .As long as the elevator is moving the torque motor acts through the rod 46 to raise the retiring cam 42 out of contact with bell crank 34 so that the interlock is .effective to prevent movement of the door latching mech-' anism 15. When the elevator is levelled at a floor the torque motor stops, and gravity aided bya tension spring 4 7 pulls down the retiring cam42to release the-door latching mechanism. A dash pot 4s connected to the crank 45 by a rod 49 dampens acceleration and deceleration of the retiring cam to provide smooth operation.

it is to be understood that conventional devices other thana torque motor could be used to control the movement of the retiring cam, such, for enamplefiisla rotary solenoid. v .7

lock member having a portion extending past the'hinge line of the door; an angle bracket having an attaching arm secured to the door frame and extending transverselypast the side of the elevator car, said bracket having a mounting arm extending rearwardly into the space ,at the side of the elevator car; abell crank pivotally mounted on. said mounting armon a horizontal axis which is in aplane parallel'to that of the interlock member, said bell crank having a locking arm in the plane of the interlock member and normally engaged therewith, andhaving an actuating arm in the space at the side ,of; the elevator car; a cam follower on said actuatingtarm in a positionwhich is clear of the mounting armyand cam means onthesideof the elevator car which contacts said cam; follower to rock the bell crank on its pivot and lift the locking armput of engagement with the interlock member ,when thecar is opposite the'hatchway door. i v

3. In an elevator unit having an elevator car mounted for movement in ahatC Way which is provided with a doorway, a door hin gedly mduntedat one side ofthe doorway, and a door latch which is engageable and disengageable from inside theelevator car by means of a pivoted inside operating arm on the door, a combined outside door operating means and safety interlock comprising: an outvside door cperating arm mounted on alpivot whichextends through said door; an inside connecting portion on sardpivot inside the-door; a link pivotally connected to said connecting portion and to said inside operating arm; an interlock member pivotally connected to said inside connecting portion and slidably supported on the inside of the door, said interlock member extending transversely past the door hinges; a supporting bracket mounted in the hatchway and having a mounting arm which is in the space at the side of the elevator car; a bell crank pivotally mounted on said mounting arm on a horizontal axis which is in a plane parallel to that of the interlock member, said bell crank having a locking arm in the plane of the interlock member and normally engaged therewith, and having an actuating arm in the space at the side of the elevator car; a cam follower on said actuating arm at a position which is clear of the mounting arm; and cam means on the side of the elevator car which contacts said cam follower to rock the bell crank on its pivot and lift the locking arm out of engagement with the interlock member when the car is opposite the hatchway door.

4. In an elevator unit having an elevator car mounted for movement in a hatchway which is provided with a doorway, a door frame surrounding the doorway, a door hingedly mounted on the frame at one side of the doorway, and a door latch which is engageable and disengageable from inside the elevator car by means of a pivoted inside operating arm on the door, a combined outside door operconnecting portion and to said inside operating arm; an interlock member pivotally connected to said inside connecting portion and slidably supported on the inside of the door, said interlock member extending transversely past the door hinges; an angle bracket having an attaching arm secured to the door frame and extending transversely past the side of the elevator car, said bracket having a mounting arm extending rearwardly into the space at the side of the elevator car; a bell crank pivotally mounted on said mounting arm on a horizontal axis which is in a plane parallel to that of the interlock member, said bell crank having a locking arm in the plane of the interlock member and normally engaged therewith, and having an actuating arm in the space at the side of the elevator car; a cam follower on said actuating arm at a position which is clear of the mounting arm; and cam means on the side of the elevator car which contacts said cam follower to rock the bell crank on its pivot and lift the locking arm out of engagement with the interlock member when the car is opposite the hatchway door.

References Cited in the file of this patent UNITED STATES PATENTS 759,479 See May 10, 1904 964,891 Westlin July 19, 1910 1,709,596 Schweig Apr. 16, 1929 2,280,805 Dodd Apr. 28, 1942 

